Patient Selection
Malcolm G. Munro MD, FACOG, FRCSC
KEY POINTS
- The success of a hysteroscopic procedure is predicated on the combination of adequate equipment and supplies along with appropriate surgical skills applied safely to properly selected patients.
- Proper patient selection requires a detailed understanding of both the symptoms and findings, the patient's short- and long-term goals, and evaluation of the uterus in a way that informs decisions regarding the procedure that should be performed.
- This evaluation will also help determine the appropriate surgeon or surgical team based on skill, location and available equipment and supplies.
- The role of hysteroscopy as a diagnostic instrument varies depending on the availability and use of sonohysterography (SHG).
- For the diagnosis of structural abnormalities such as polyps and leiomyomas sonohysterography (SHG) is as sensitive as hysteroscopy.
- When considering hysteroscopic myomectomy, it is important to perform imaging techniques to identify and exclude individuals with FIGO Type 2-5 tumors as well as those with an outer free margin too narrow for safe hysteroscopically-directed removal.
- Women with postmenopausal bleeding can be primarily evaluated with either TVUS or blind biopsy, but hysteroscopy has a role, particularly when sonographic findings suggest the presence of an intrauterine polyp.
- If intrauterine adhesions are known or suspected to interfere with fertility it is important to evaluate the patient carefully but understand that it is difficult to predict the extent of adhesions preoperatively. This argues for referral to centers of excellence either when HSG shows extensive adhesions, or when it is difficult to evaluate the extent of disease when cervical occlusion prevention detailed preprocedural evaluation of the endometrial cavity.
- Prehysteroscopic evaluation of the endometrial cavity with SHG can help determine the required surgical complexity for removal of endometrial polyps.
- The Müllerian anomaly treatable hysteroscopically is a rAFS Class V, also categorized in CONUTA as a U2 lesion. It is important to ensure that the uterine corpus is unified before performing hysteroscopic transaction of the septum using either 3D-Ultrasound or MRI.
- Hysteroscopic techniques have a role in the management of retained products of conception, but both specific equipment and patients with relatively low volume tissue are necessary for what we understand to be an optimal outcome.
INTRODUCTION
Hysteroscopy has an important role for selected women with infertility, recurrent pregnancy loss, retained products of conception, postmenopausal bleeding, AUB in the reproductive years, and those with a retained intrauterine contraceptive system. The hysteroscope may be used either as a diagnostic instrument or to direct the performance of a spectrum of intrauterine procedures. The utility of diagnostic hysteroscopy will vary depending on a number of factors. For example, for those clinicians who have ready access to transvaginal ultrasound, and who have learned the techniques of sonohysterography(SHG), the role of hysteroscopy as a diagnostic instrument may be limited to those occasions where sonographic-based imaging is inconclusive. On the other hand, when transvaginal ultrasound is not as readily available, hysteroscopic diagnosis becomes more important. In any instance, hysteroscopic surgery is a critically important approach to uterine disorders that allows targeted therapy through an existing orifice, obviating the need for incisions. This indeed is the very epitome of minimal access surgery and it deserves to be an integral part of the definition of a minimally invasive gynecologic surgeon.
This ready portal of access to the endometrial cavity does not obviate the need to carefully assess women to determine first if surgery is necessary and second if the hysteroscopic approach is appropriate for the disorder at hand. This process requires a careful evaluation of symptoms and the results of clinical and appropriate laboratory and imaging findings so that the patient can be counseled in a fashion that will help her make an informed decision. It will also be the foundation for a safe and effective procedure if performed by an appropriately trained surgeon.
WHICH PATIENTS ARE APPROPRIATE FOR HYSTEROSCOPIC SURGERY?
There exists a spectrum of uterine conditions that may be safely and effectively remedied by hysteroscopic surgery – these are summarized in the accompanying table.
| Category | Specific Indication | Hysteroscopic Procedure |
|---|---|---|
| Premenarcheal Vaginal Bleeding | Diagnostic for vaginal bleeding | Diagnostic vaginoscopy, biopsy, foreign body removal |
| AUB in the Reproductive Years | Evaluation for cause | Endometrial ablation for selected AUB-A; Lsm, C, O, and E cases |
| Postmenopausal Bleeding | Evaluation for cause | Diagnostic with targeted endometrial / endocervical biopsy |
| Adhesions, Intrauterine | Infertility | Intrauterine adhesiolysis |
| Leiomyomas | AUB, infertility, recurrent preganncy loss associated with FIGO Types 0, 1, 2 and occasionally 3 | Myomectomy |
| Polyps | Endometrial and Endocervical | Polypectomy |
| Müllerian Absorption Anomalies | rAFS Type IV (CONUTA U2); Selected others | Transaction of uterine septum ± cervical septum |
| Retained Intrauterine Device | Failed "blind" removal | Targeted removal of IUD |
| Retained Products of Conception | Delayed (not immediate post partum) | Targeted removal of POC |
| "Second Look" | Evaluation post surgery or other intervention | Identification of adhesions ± transaction |
For example, it is clear that when surgical removal is indicated for endometrial or endocervical polyps that the targeted, hysteroscopic approach is effectively the only choice. However, when it is necessary to perform myomectomy on a submucous leiomyoma, careful investigation must be performed to determine if specific features, including the FIGO Type, uterine location and lesional size, are within the skill set of a given surgeon, or any surgeon at all. Consequently, given a symptom or uterine finding, it is necessary to get as much detail as necessary in addition to a detailed understanding of the patient’s goals, timing of those goals, and then to couple this with investigation that is largely based around imaging. And the surgeon MUST be intimately involved in the imaging process – just the way any orthopedic or neurosurgeon is. You can’t make decisions off of reports.
SYMPTOM-SPECIFIC EVALUATION
The initial symptoms we will discuss are those of abnormal uterine bleeding (AUB) which is the symptom most likely to lead to hysteroscopic evaluation for most gynecologists. At a "high level" these symptoms can be categorized as premenarcheal, postmenopausal, and non gestational AUB in the reproductive years, each of which has a different investigative pathway (See figure). Fundamentally, the plan is to identify the cause of the bleeding, and, from a hysteroscopic perspective, determine which patients might benefit from intrauterine evaluation or surgery.
Premenarcheal Bleeding
Whereas most gynecologists will not deal with pediatric premenarcheal patients, it is useful to understand some of the basic issues that should be addressed should their parent present reporting bleeding or discharge. The most common contributors to discharge or bleeding are vulvovaginal infections and inflammation which comprise about half of the cases, while foreign bodies, vaginal tumors, endogenous and exogenous estrogens and trauma, including that which results from sexual abuse, contributing the rest. In older girls, idiopathic precocious menstruation is commonly encountered. Regardless, the hysteroscope has in important place in the evaluation of selected individuals with these symptoms, not so much for evaluation of the uterus, but, using the vaginoscopic technique, for evaluating the vagina and cervix where targeted biopsy, or, more commonly, endoscopically directed removal of foreign bodies is facilitated. The gynecologist must remember that, for pediatric patients, there is a variable difference between the one presenting the symptoms and the patient herself, so empathy and patience must be practiced and demonstrated during this process. Please see the section on Pediatric Evaluation for more detail.
Abnormal Uterine Bleeding (AUB) in the Reproductive Years
Girls and women with AUB in the reproductive years must have their symptoms systematically assessed using FIGO AUB System 1, and should be evaluated appropriately for lower genital tract, perineal and perianal sources of their bleeding. They must also be assessed for pregnancy using an appropriate test for 𝛽hCG.
Once it has been ascertained that bleeding is coming from within the uterus FIGO’s System 2 (PALM-COEIN) should be used to guide the steps necessary to determine potential causes of the AUB. Many of these steps are guided by the System 1 evaluation. For example, women with irregular bleeding are far more likely to have an ovulatory disorder (AUB-O) and those with a lifelong history of the symptom of heavy menstrual bleeding (HMB) should be evaluated for the presence of a systemic disorder of hemostasis – a coagulopathy. There will be those who are at risk for the presence of endometrial intraepithelial neoplasia or cancer for whom endometrial sampling, either blind or targeted, will be necessary at some point in the evaluation. These will include those with a longstanding ovulatory disorder, even if in her 20s or 30s, and particularly if obese, as well as most individuals with at least irregular uterine bleeding above the age of 45. Whereas there will be those for whom TVUS is inappropriate (eg. virginal) or largely unnecessary for an initial evaluation (eg late teens or 20s), for most, and particularly if readily available (in the consulting room) transvaginal ultrasound will be useful to evaluate for structural anomalies.
If structural abnormalities of the uterus are suggested with TVUS – and these include polyps (P), adenomyosis (A), leiomyomas (L), endometrial hyperplasia or malignancy (M) and the cesarean scare defect (which is currently contained in N), it may be necessary to further clarify their characteristics with additional imaging studies. For example, it may be difficult to distinguish between a polyp and endometrial thickness. Another common example are leiomyomas – submucous leiomyomas are those thought to contribute to AUB, while those that are intramural (Type 4) or submucous (Types 5, 6, and &) are thought not to cause abnormal bleeding symptoms.
The most readily available means by which this evaluation can be performed is using sonohysterography (SHG), particularly if the examiner has ultrasound immediately available in the office or clinic. A simple insemination catheter can be placed in the uterus, attached to a 20-30 mL syringe filled with Normal Saline, and under TVUS guidance the solution injected to provide intrauterine contrast. An alternative approach is to use sterile gel, including 2% lidocaine gel, which will generally stay within the endometrial cavity allowing the study to be performed without having to maintain the catheter in place. With this approach endometrial thickening can be distinguished from endometrial polyps, and the location, phenotype number, and volume of polyps can be determined. When leiomyomas are difficult to see with TVUS, or are shown to be close to the endometrial cavity, SHG will allow the examiner to determine the involvement of the endometrial cavity to help distinguish amongst Types 0, 1, 2, and 3 tumors, and may allow for assessment of the outer free margin (OFM) of Type 2 lesions that are identified. Indeed, the OFM is critical not only to aid in the identification of Type 2-5 tumors, but in determining Type 2 lesions that are appropriate for hysteroscopic technique. This can help determine when referral to individuals with more skill and expertise may be necessary. If SHG is not determinative, then MRI may be needed for this purpose.
For women or girls with the symptom of HMB, and when uterine imaging is either normal or where it is likely that structural abnormalities seen are not related to the bleeding, then AUB-C, O and E must be considered. It is likely that the incidence of AUB-E is higher than perceived as many women with HMB without structural abnormalities are portrayed as being “normal? Such women will not benefit from hysteroscopic surgery with the exception of endometrial ablation which is reserved for those who wish never to become pregnant.
Postmenopausal Bleeding
With women in their late fifth and sixth decades of life is sometimes difficult for clinicians to distinguish between those who have AUB in the context of ovarian estradiol production, and those who are postmenopausal with no such production – the age of menopause varies widely. Consequently, the clinician should take steps to determine the ovarian status, preferably with the measurement of serum estradiol, if there is any question, for this is an important aspect of the evaluation. A second important point is that women who are using cyclically administered progestins in the context of menopausal hormone replacement may expect withdrawal bleeding – this is not abnormal and requires no investigation.
For those who are deemed to be postmenopausal, and who have spontaneous bleeding, there are really two approaches to consider. One is endometrial sampling - either performed blindly, or under hysteroscopic direction. The other pathway is to start with transvaginal ultrasound, and, if an endometrial echo complex (EEC) can be seen in its entirety, to use the appearance, and, in particular the echogenic thickness (from basilar layer to the opposing basilar layer) to triage women. Those with an EEC 4 mm or less in thickness have an extremely low incidence of intrauterine pathology and hyperplasia or cancer and can be safely handled expectantly. Those for whom the EEC cannot be well seen, or who have a thickness in excess of 4 mm should have further assessment that includes endometrial sampling. That further assessment could include SIS, that could be done contemporaneously with the endometrial sampling, or could be performed hysteroscopically. Either approach might identify evidence of an endometrial polyp that could be removed via a hysteroscopic approach.
Intrauterine Adhesions (Asherman Syndrome)
Women with intrauterine adhesions will usually present either with infertility or light or absent menstrual bleeding. In most instances there will be a history of a recent pregnancy and/or surgery that affects the endometrial cavity. It is generally suggested that a hysterosalpingogram be performed to provide as much information as possible regarding the situation within the endometrial cavity and to determine if there is evidence of unilateral or bilateral tubal patency. If the cervical canal or lower uterine segment are involved with completely occlusive adhesions, there will be no opportunity for imaging the endometrial cavity. Endometrium may be seen via TVUS and provide some indirect evidence of the extent of involvement.
Clearly relatively minor degrees of involvement may be relatively easy to deal with, but if there is suspicion of moderate or extensive adhesions it is suggested that the procedure be done in an environment where there are facilities that allow intraprocedure imaging by or with individuals with experience with such cases.
Leiomyomas
Much of the guidance for evaluation of patients for the presence of leiomyomas has been discussed above under AUB. The patient who will benefit from hysteroscopic myomectomy will have a submucous leiomyoma, resectable by hysteroscopic technique AND have one or more of the following: infertility, recurrent pregnancy loss and the symptom of HMB. If fertility is not desired – then there may be medical or other procedural options that are acceptable – even more acceptable for the patient. There may be other factors impacting the overall decision including the presence of other leiomyomas, such as Types 4 to 7 that may be causing bulk symptoms better treated with an alternative approach. Regardless, the information must be processed by the clinician and then presented to the patient in a fashion that allows for making an informed decision.
From a surgical perspective the information obtained in the investigation will allow the determination of a number of important factors. First, is the leiomyoma safely resectable by hysteroscopic technique? Second, is the technique within the skill set of the clinician and her or his hysteroscopic team? Third, will intraoperative ultrasonic guidance be needed? Fourth, if resection is to be performed, what technique will be used and where will the procedure be performed? More discussion on hysteroscopic myomectomy is to be found elsewhere in this site.
Polyps
As was the case with leiomyomas (above) the investigation resulting in the diagnosis of an endometrial or endocervical polyp has been discussed in the section on AUB. The issue with polyps is not really can they be removed hysteroscopically, it is how. If the diagnosis is made hysteroscopically it is preferable that the polypectomy be performed at the same setting. If the diagnosis can be made prior to the hysteroscopic procedure, then accommodations can be made for technique – relatively small polyps can be transected with simple hysteroscopic scissors and removed with grasping forceps. However, when the polyps are large, sessile, are numerous, other techniques may be more efficient and effective. The more information available prior to the hysteroscopy the better prepared the team and the patient. More on polyps can be found elsewhere in this site.
Müllerian Fusion and Absorption Defects
Congenital uterine abnormalities that result from failure of absorption of the wall between the two fused Müllerian ducts and which can be addressed hysteroscopically are generally asymptomatic – with the exception of recurrent pregnancy loss (RPL). Consequently, the diagnosis usually is suggested after investigation for either infertility or RPL. Appropriate indications may include recurrent pregnancy loss, and, although infertility is not likely caused by these defects, there is an argument for preemptive transaction of septums for rAFS Class 5 / CONUTA U2 anomalies to reduce the risk of spontaneous abortion. However, it is important that the precise diagnosis is made since hysteroscopically Class 3, 4 and 5 (CONUTA U2 and 3) anomalies appear to be similar, and the peritoneal cavity will be entered if there is attempted transaction of a Class 4 or 4 (CONUTA U3) anomaly. Previously this distinction had to be made laparoscopically, but 3-D TVUS or MRI are superior in that they are at least as accurate and utilize far fewer resources provided the hysteroscopic transaction is performed in a low resource environment. More on this can be found in the section on hysteroscopic transaction of the uterine septum.
Retained Intrauterine Device
Hysteroscopically directed removal of the retained IUD is a procedure particularly suited to an office or clinic-based service. However, the process is not without peril so it is important to evaluate the patient carefully prior to removing the device. First of all, it is important to perform TVUS to determine that indeed the device is in the uterus – in some instances patients are unaware that the device has been expelled, or, less commonly, it may be inaccessible to hysteroscopic removal because it is in the myometrium, or the peritoneal cavity. Another circumstance can occur if there has been partial perforation laterally, near the uterine vessels, a circumstance that may be associated with a theoretical risk of bleeding if removal is performed hysteroscopically. All of these issues are part of the patient assessment and designed to foster a safe and successful procedure and an informed consent process.
Retained Products of Conception
The precise role for hysteroscopic technique in removing products of conception is not clearly defined. However, there is evidence that targeted removal is associated with a reduced risk of intrauterine adhesions, a reduction that could impact future fertility. Hysteroscopic technique may not be well suited to the early postpartum timeframe, or when there are large volumes of placental tissue in the uterus. Furthermore, it appears necessary to have either a uterine resectoscope, for which a loop electrode is used WITHOUT activation (cold loop) or an electromechanical uterine tissue removal system. Consequently, and provided this type of instrumentation is available, the patient should be carefully evaluated with TVUS to determine the volume of tissue likely present. No firm guidelines exist, but EEC thickness beyond 2 cm will be challenging for the technique and suggest that sonographically directed suction, or a hybridized suction/hysteroscopic technique may be most appropriate.
CONTRAINDICATIONS to HYSTEROSCOPY
Few circumstances exist where hysteroscopy is contraindicated. These limited instances include acute uteropelvic infections such as pelvic inflammatory disease, and, of course, cervical hypoplasia or agenesis that prevent access to the endometrial cavity. Another “contraindication” os known or suspected viable intrauterine pregnancy but an exception exists when hysteroscopy is utilized to remove an intrauterine system in selected pregnant patients. Hysteroscopy has been considered contraindicated for pediatric patients and other virginal females, but using the “vaginoscopic” access technique, examination of the vagina, cervical canal and endometrial cavity may be accomplished without disturbing the integrity of the hymeneal ring.
CONCLUSION
Like all surgical procedures, successful, safe and effective hysteroscopy and hysteroscopic surgery are dependent upon careful patient selection. This means that the patient is carefully evaluated in a fashion that determines whether or not hysteroscopic surgery offers her the opportunity to improve her fertility or quality of life with an intrauterine surgical intervention. Identification of the appropriate patient allows for an appropriate process of informed consent.
